1. Field of the Invention
The present invention relates to a charge display unit of an electric vehicle, and particularly to a charge display unit of an electric vehicle charged by a plurality of charge sources.
2. Description of the Background Art
Today, in an electric vehicle which uses electric power charged in a battery as a drive source for driving a motor to thereby obtain power, the battery can be charged by a household power supply through a cable. In recent years, more and more homes employ private power generation using photovoltaic power generation or wind power generation. In a case where the homes have any surplus electric power, the surplus electric power is sold to an electric power company, and in a case where the amount of power generation is insufficient, the homes use commercial electric power (system electric power) supplied from an electric power supply system of an electric power company. Advanced version of such a system is a next-generation electric power network called a smart grid.
In the current situation where homes are introducing electric power supply based on private power generation, when a battery of an electric vehicle is charged by a household power supply, there are cases where the charged electric power is obtained by photovoltaic power generation or wind power generation and where the charged electric power is obtained by an electric power supply system. Even in the case of the system electric power, the price varies between day and night. Thus, there are cases of normal system electric power and night system electric power. Additionally, in a case of quick charge, the charge may be performed in a quick charger by paying an additional fee.
In this manner, in an electric vehicle (including a plug-in hybrid vehicle which uses both of a gasoline engine and a motor), electric power is charged by a plurality of supply sources, and the running cost varies depending on which of the supply sources is selected. The running cost of an electric vehicle is represented by, for example, the term “electricity cost”, which is, similarly to the fuel cost in a gasoline vehicle, a matter of concern to a user.
However, in a conventional electric vehicle as disclosed in Japanese Patent Application Laid-Open No. 2010-149553 (FIG. 2) for example, although a display of a battery charge state has been proposed, no display of the running cost such as the electricity cost has not been proposed.